Pretty solid port.
The onscreen buttons and directional pad may not be the prettiest things in the world, but they do get the job done. Of course, that is once you realize the in-game text doesn't apply to the control scheme on iOS. The "running like a dog" action (sprint) is tied to a button above the jump button, and instead of using a button to look down, you actually use the native pinch to zoom and vice versa to see more around you. It's cool.
As far as the game's concerned, I'd rather not have access to all 22 levels from the get-go, but what can you do? :/ Tons of platforming and exploration in massive levels, hidden locations, B-O-N-U-S (letter) collection, boss battles, trying to fill a quota (of bones and food) up to 100% in each level, no IAPS.
If you're into SNES era platformers, you'll dig this a lot!